Crystal structure of the homo-tetrameric DNA binding domain of Escherichia coli single-stranded DNA-binding protein determined by multiwavelength x-ray diffraction on the selenomethionyl protein at 2.9-A resolution.

abstract：:In a coupled system consisting of RNA polymerase and DNA polymerase I of Escherichia coli, the four deoxyribo- and the four ribonucleoside triphosphates, and DNA of bacteriophage f1 as template, DNA synthesis depends on the concomitant synthesis of RNA. Over a wide range of concentrations of the two polymerases, RNA s...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Karkas JD

更新日期：1972-08-01 00:00:00

abstract：:Skeletal muscle L-type Ca2+ channels respond to trains of brief depolarizations with a strong shift of the voltage dependence of channel activation toward more negative membrane potentials and slowing of channel deactivation. Increased Ca2+ entry resulting from this potentiation of channel activity may increase contra...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Johnson BD,Scheuer T,Catterall WA

更新日期：1994-11-22 00:00:00

abstract：:RNA molecules that bind a transition state analog for a Diels-Alder reaction (Kd = 0.35 +/- 0.05 mM) were isolated from a starting pool of approximately 10(14) sequences by affinity chromatography. After the initial rise and plateau of the amount of RNA that eluted with soluble analog, a step gradient elution was used...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Morris KN,Tarasow TM,Julin CM,Simons SL,Hilvert D,Gold L

更新日期：1994-12-20 00:00:00

abstract：:Ca(2+)-sensitive kinases are thought to play a role in long-term potentiation (LTP). To test the involvement of Ca2+/calmodulin-dependent kinase II (CaM-K II), truncated, constitutively active form of this kinase was directly injected into CA1 hippocampal pyramidal cells. Inclusion of CaM-K II in the recording pipette...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Lledo PM,Hjelmstad GO,Mukherji S,Soderling TR,Malenka RC,Nicoll RA

更新日期：1995-11-21 00:00:00

abstract：:Several cDNA clones encoding the human immunoglobulin G receptor CD16 were isolated from human lung or peripheral blood leukocyte cDNA libraries. Nucleotide sequence comparisons revealed that the cDNAs could be divided into two groups. cDNA clones in one group encode a protein that terminates 4 amino acids after the p...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Scallon BJ,Scigliano E,Freedman VH,Miedel MC,Pan YC,Unkeless JC,Kochan JP

更新日期：1989-07-01 00:00:00

abstract：:A search for potent toxins that inhibit neuronal calcium channels in Drosophila melanogaster has resulted in the identification of a presynaptic neurotoxin from the venom of the hunting spider Hololena curta. Using Drosophila neuromuscular junction as an assay, presynaptic inhibitory activity was purified using gel fi...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Bowers CW,Phillips HS,Lee P,Jan YN,Jan LY

更新日期：1987-05-01 00:00:00

abstract：:Germ-line mutations of tumor suppressor genes confer strong predisposition to tumor formation. In the rat, a form of dominantly inherited renal carcinoma (RC) results in multiple chromophobe cell tumors that resemble the human disease, and heterozygous carriers (RC/+) are highly susceptible to environmental agents (ra...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Yeung RS,Buetow KH,Testa JR,Knudson AG Jr

更新日期：1993-09-01 00:00:00

abstract：:In this model gravitation results from the emission and absorption of quanta (gravitons) that are scattered a few times in crossing a typical galaxy. Many features of the universe can be explained in terms of this model, although theoretical justification for the scattering of gravitons is lacking. Gravitons follow a ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Britten RJ

更新日期：1992-05-01 00:00:00

abstract：:Interdigital webbing has evolved repeatedly in tropical salamanders (bolitoglossines). This derived foot morphology is only one of many homoplastic traits in this diverse amphibian clade. Indeed, few if any morphological traits sort lineages within this clade. We investigate the processes underlying the homoplastic ev...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Jaekel M,Wake DB

更新日期：2007-12-18 00:00:00

abstract：:p300 acetylates and activates the tumor suppressor p53 after DNA damage. Here, we show that MDM2, a negative-feedback regulator of p53, inhibited p300-mediated p53 acetylation by complexing with these two proteins. First, we purified a p300-MDM2-p53 protein complex from HeLa nuclear extracts, which was inactive in p53...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kobet E,Zeng X,Zhu Y,Keller D,Lu H

更新日期：2000-11-07 00:00:00

abstract：:Sodium/hydrogen exchangers (NHEs) are ubiquitous ion transporters that serve multiple cell functions. We have studied two mammalian isoforms, NHE1 (ubiquitous) and NHE3 (epithelial-specific), by measuring extracellular proton (H+) gradients during whole-cell patch clamp with perfusion of the cell interior. Maximal Na(...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Fuster D,Moe OW,Hilgemann DW

更新日期：2004-07-13 00:00:00

abstract：:We provide evidence that citrate anions bridge between mineral platelets in bone and hypothesize that their presence acts to maintain separate platelets with disordered regions between them rather than gradual transformations into larger, more ordered blocks of mineral. To assess this hypothesis, we take as a model fo...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Davies E,Müller KH,Wong WC,Pickard CJ,Reid DG,Skepper JN,Duer MJ

更新日期：2014-04-08 00:00:00

abstract：:The electrical currents at the surface of the proximal portion of an isolated and transected lamprey spinal cord were measured with an extracellular vibrating probe. Soon after transection, currents of about 0.5 mA/cm2 enter the cut surface of the spinal cord. These currents fall to about a quarter of their initial va...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Borgens RB,Jaffe LF,Cohen MJ

更新日期：1980-02-01 00:00:00

abstract：:Thiamin diphosphate, the vitamin B1 coenzyme, plays critical roles in fundamental metabolic pathways that require acyl carbanion equivalents. Studies on chemical models and enzymes had suggested that these carbanions are resonance-stabilized as enamines. A crystal structure of this intermediate in pyruvate oxidase at ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Meyer D,Neumann P,Koers E,Sjuts H,Lüdtke S,Sheldrick GM,Ficner R,Tittmann K

更新日期：2012-07-03 00:00:00

abstract：:Secretions of the uterus support survival and growth of the conceptus (embryo/fetus and associated membranes) during pregnancy. Galectin-15, also known as OVGAL11 and a previously uncharacterized member of the galectin family of secreted beta-galactoside lectins containing a conserved carbohydrate recognition domain a...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Gray CA,Adelson DL,Bazer FW,Burghardt RC,Meeusen EN,Spencer TE

更新日期：2004-05-25 00:00:00

abstract：:Aquaporin (AQP) 4 is the predominant water channel in the mammalian brain, abundantly expressed in the blood-brain and brain-cerebrospinal fluid interfaces of glial cells. Its function in cerebral water balance has implications in neuropathological disorders, including brain edema, stroke, and head injuries. The 1.8-A...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ho JD,Yeh R,Sandstrom A,Chorny I,Harries WE,Robbins RA,Miercke LJ,Stroud RM

更新日期：2009-05-05 00:00:00

abstract：:An established line of mouse fibroblasts, C3H/10T1/2 cells, was used for the assessment in vitro of oncogenic transformations caused by single and split doses of x-rays. The shape of the dose-response relationship was determined over the range from 0.1 to 10 Gy. It was found that splitting the x-ray dose into two equa...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Miller RC,Hall EJ,Rossi HH

更新日期：1979-11-01 00:00:00

abstract：:The cellular response to ionizing radiation (IR) includes induction of the c-jun and EGR1 early response genes. The present work has examined potential cytoplasmic signaling cascades that transduce IR-induced signals to the nucleus. The results demonstrate activation of the 40S ribosomal protein S6 kinase, pp90rsk, in...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kharbanda S,Saleem A,Shafman T,Emoto Y,Weichselbaum R,Kufe D

更新日期：1994-06-07 00:00:00

abstract：:Ras proteins are small GTP binding proteins that serve as critical relays in a variety of signal transduction pathways in eukaryotic cells. Like most metazoan Ras proteins, yeast Ras is post-translationally modified by addition of a farnesyl and a palmitoyl moiety, and these modifications are required for targeting th...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Bhattacharya S,Chen L,Broach JR,Powers S

更新日期：1995-03-28 00:00:00

abstract：:Type VI protein secretion system (T6SS) is important for bacterial competition through contact-dependent killing of competitors. T6SS delivers effectors to neighboring cells and corresponding antagonistic proteins confer immunity against effectors that are delivered by sister cells. Although T6SS has been found in mor...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Dong TG,Ho BT,Yoder-Himes DR,Mekalanos JJ

更新日期：2013-02-12 00:00:00

abstract：:The wide diversity of dendritic trees is one of the most striking features of neural circuits. Here we develop a general quantitative theory relating the total length of dendritic wiring to the number of branch points and synapses. We show that optimal wiring predicts a 2/3 power law between these measures. We demonst...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Cuntz H,Mathy A,Häusser M

更新日期：2012-07-03 00:00:00

abstract：:A Down's syndrome associated gene, Single Minded 2 gene short form (SIM2-s), is specifically expressed in colon tumors but not in the normal colon. Antisense inhibition of SIM2-s in a RKO-derived colon carcinoma cell line causes growth inhibition, apoptosis, and inhibition of tumor growth in a nude mouse tumoriginicit...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Aleman MJ,DeYoung MP,Tress M,Keating P,Perry GW,Narayanan R

更新日期：2005-09-06 00:00:00

abstract：:A long (20-30 micrometer), wide (3-5 micrometer) microbial-mat bacterium from the Ebro Delta (Tarragona, Spain) was grown in mixed culture and videographed live. Intracellular elemental sulfur globules and unique cell termini were observed in scanning-electron-microprobe and transmission-electron micrographs. A polar ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Guerrero R,Haselton A,Solé M,Wier A,Margulis L

更新日期：1999-09-28 00:00:00

abstract：:The size and metabolic rate of cells affect processes from the molecular to the organismal level. We present a quantitative, theoretical framework for studying relationships among cell volume, cellular metabolic rate, body size, and whole-organism metabolic rate that helps reveal the feedback between these levels of o...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Savage VM,Allen AP,Brown JH,Gillooly JF,Herman AB,Woodruff WH,West GB

更新日期：2007-03-13 00:00:00

abstract：:Particles composed of secondary organic material (SOM) are abundant in the lower troposphere. The viscosity of these particles is a fundamental property that is presently poorly quantified yet required for accurate modeling of their formation, growth, evaporation, and environmental impacts. Using two unique techniques...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Renbaum-Wolff L,Grayson JW,Bateman AP,Kuwata M,Sellier M,Murray BJ,Shilling JE,Martin ST,Bertram AK

更新日期：2013-05-14 00:00:00

abstract：:Adult workers in honeybee (Apis mellifera) colonies exhibit plasticity in hormonally regulated, age-based division of labor by altering their pattern of behavioral development in response to changes in colony conditions. One form of this plasticity is precocious development: levels of juvenile hormone increase prematu...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Huang ZY,Robinson GE

更新日期：1992-12-15 00:00:00

abstract：:Linkage disequilibrium between polymorphisms in a natural population may result from various evolutionary forces, including random genetic drift due to sampling of gametes during reproduction, restricted migration between subpopulations in a subdivided population, or epistatic selection. In this report, we present evi...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kirby DA,Muse SV,Stephan W

更新日期：1995-09-26 00:00:00

abstract：:Sex determination in mammals is governed by antagonistic interactions of two genetic pathways, imbalance in which may lead to disorders/differences of sex development (DSD) in human. Among 46,XX individuals with testicular DSD (TDSD) or ovotesticular DSD (OTDSD), testicular tissue is present in the gonad. Although the...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Eozenou C,Gonen N,Touzon MS,Jorgensen A,Yatsenko SA,Fusee L,Kamel AK,Gellen B,Guercio G,Singh P,Witchel S,Berman AJ,Mainpal R,Totonchi M,Mohseni Meybodi A,Askari M,Merel-Chali T,Bignon-Topalovic J,Migale R,Costanzo

更新日期：2020-06-16 00:00:00

abstract：:Conventional asymmetric PCR is inefficient and difficult to optimize because limiting the concentration of one primer lowers its melting temperature below the reaction annealing temperature. Linear-After-The-Exponential (LATE)-PCR describes a new paradigm for primer design that renders assays as efficient as symmetric...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Sanchez JA,Pierce KE,Rice JE,Wangh LJ

更新日期：2004-02-17 00:00:00

abstract：:The pineal organ of the lizard Anolis carolinensis can be maintained for up to 10 days in superfused organ culture. During this time it synthesizes and releases melatonin into the medium flowing slowly over it. Collection of timed aliquots of medium and subsequent analysis for melatonin by radioimmunoassay reveal circ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Menaker M,Wisner S

更新日期：1983-10-01 00:00:00